[dev.typeparams] go/types: make TestManual work for directories

This is a port of CL 315769 to go/types, adjusted for the additional
testPkg indirection in go/types on top of testFiles, and to remove the
colDelta argument.

Change-Id: Ieb722d77866313a01645aeec49912c16cb475462
Reviewed-on: https://go-review.googlesource.com/c/go/+/324730
Trust: Robert Findley <rfindley@google.com>
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>

src/go/types/check_test.go

@@ -202,7 +202,7 @@ func asGoVersion(s string) string {
 	return ""
 }
 
-func checkFiles(t *testing.T, sizes Sizes, goVersion string, filenames []string, srcs [][]byte, manual bool) {
+func testFiles(t *testing.T, sizes Sizes, filenames []string, srcs [][]byte, manual bool) {
 	if len(filenames) == 0 {
 		t.Fatal("no source files")
 	}
@@ -225,6 +225,7 @@ func checkFiles(t *testing.T, sizes Sizes, goVersion string, filenames []string,
 	}
 
 	// if no Go version is given, consider the package name
+	goVersion := *goVersion
 	if goVersion == "" {
 		goVersion = asGoVersion(pkgName)
 	}
@@ -297,29 +298,48 @@ func checkFiles(t *testing.T, sizes Sizes, goVersion string, filenames []string,
 	}
 }
 
-// TestManual is for manual testing of input files, provided as a list
-// of arguments after the test arguments (and a separating "--"). For
-// instance, to check the files foo.go and bar.go, use:
+// TestManual is for manual testing of a package - either provided
+// as a list of filenames belonging to the package, or a directory
+// name containing the package files - after the test arguments
+// (and a separating "--"). For instance, to test the package made
+// of the files foo.go and bar.go, use:
 //
 // 	go test -run Manual -- foo.go bar.go
 //
-// Provide the -verify flag to verify errors against ERROR comments in
-// the input files rather than having a list of errors reported.
-// The accepted Go language version can be controlled with the -lang flag.
+// If no source arguments are provided, the file testdata/manual.go2
+// is used instead.
+// Provide the -verify flag to verify errors against ERROR comments
+// in the input files rather than having a list of errors reported.
+// The accepted Go language version can be controlled with the -lang
+// flag.
 func TestManual(t *testing.T) {
+	testenv.MustHaveGoBuild(t)
+
 	filenames := flag.Args()
 	if len(filenames) == 0 {
-		return
+		filenames = []string{filepath.FromSlash("testdata/manual.go2")}
 	}
-	testenv.MustHaveGoBuild(t)
+
+	info, err := os.Stat(filenames[0])
+	if err != nil {
+		t.Fatalf("TestManual: %v", err)
+	}
+
 	DefPredeclaredTestFuncs()
-	testPkg(t, filenames, *goVersion, true)
+	if info.IsDir() {
+		if len(filenames) > 1 {
+			t.Fatal("TestManual: must have only one directory argument")
+		}
+		testDir(t, filenames[0], true)
+	} else {
+		testPkg(t, filenames, true)
+	}
 }
 
 func TestLongConstants(t *testing.T) {
 	format := "package longconst\n\nconst _ = %s\nconst _ = %s // ERROR excessively long constant"
 	src := fmt.Sprintf(format, strings.Repeat("1", 9999), strings.Repeat("1", 10001))
-	checkFiles(t, nil, "", []string{"longconst.go"}, [][]byte{[]byte(src)}, false)
+	testFiles(t, nil, []string{"longconst.go"}, [][]byte{[]byte(src)}, false)
 }
 
 // TestIndexRepresentability tests that constant index operands must
@@ -327,7 +347,7 @@ func TestLongConstants(t *testing.T) {
 // represent larger values.
 func TestIndexRepresentability(t *testing.T) {
 	const src = "package index\n\nvar s []byte\nvar _ = s[int64 /* ERROR \"int64\\(1\\) << 40 \\(.*\\) overflows int\" */ (1) << 40]"
-	checkFiles(t, &StdSizes{4, 4}, "", []string{"index.go"}, [][]byte{[]byte(src)}, false)
+	testFiles(t, &StdSizes{4, 4}, []string{"index.go"}, [][]byte{[]byte(src)}, false)
 }
 
 func TestIssue46453(t *testing.T) {
@@ -335,17 +355,17 @@ func TestIssue46453(t *testing.T) {
 		t.Skip("type params are enabled")
 	}
 	const src = "package p\ntype _ comparable // ERROR \"undeclared name: comparable\""
-	checkFiles(t, nil, "", []string{"issue46453.go"}, [][]byte{[]byte(src)}, false)
+	testFiles(t, nil, []string{"issue46453.go"}, [][]byte{[]byte(src)}, false)
 }
 
-func TestCheck(t *testing.T)     { DefPredeclaredTestFuncs(); testDir(t, "check") }
-func TestExamples(t *testing.T)  { testDir(t, "examples") }
-func TestFixedbugs(t *testing.T) { testDir(t, "fixedbugs") }
+func TestCheck(t *testing.T)     { DefPredeclaredTestFuncs(); testDirFiles(t, "testdata/check", false) }
+func TestExamples(t *testing.T)  { testDirFiles(t, "testdata/examples", false) }
+func TestFixedbugs(t *testing.T) { testDirFiles(t, "testdata/fixedbugs", false) }
 
-func testDir(t *testing.T, dir string) {
+func testDirFiles(t *testing.T, dir string, manual bool) {
 	testenv.MustHaveGoBuild(t)
+	dir = filepath.FromSlash(dir)
 
-	dir = filepath.Join("testdata", dir)
 	fis, err := os.ReadDir(dir)
 	if err != nil {
 		t.Error(err)
@@ -355,28 +375,38 @@ func testDir(t *testing.T, dir string) {
 	for _, fi := range fis {
 		path := filepath.Join(dir, fi.Name())
 
-		// if fi is a directory, its files make up a single package
-		var filenames []string
+		// If fi is a directory, its files make up a single package.
 		if fi.IsDir() {
-			fis, err := os.ReadDir(path)
-			if err != nil {
-				t.Error(err)
-				continue
-			}
-			for _, fi := range fis {
-				filenames = append(filenames, filepath.Join(path, fi.Name()))
-			}
+			testDir(t, path, manual)
 		} else {
-			filenames = []string{path}
+			t.Run(filepath.Base(path), func(t *testing.T) {
+				testPkg(t, []string{path}, manual)
+			})
 		}
-		t.Run(filepath.Base(path), func(t *testing.T) {
-			testPkg(t, filenames, "", false)
-		})
 	}
 }
 
+func testDir(t *testing.T, dir string, manual bool) {
+	testenv.MustHaveGoBuild(t)
+
+	fis, err := os.ReadDir(dir)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+
+	var filenames []string
+	for _, fi := range fis {
+		filenames = append(filenames, filepath.Join(dir, fi.Name()))
+	}
+
+	t.Run(filepath.Base(dir), func(t *testing.T) {
+		testPkg(t, filenames, manual)
+	})
+}
+
 // TODO(rFindley) reconcile the different test setup in go/types with types2.
-func testPkg(t *testing.T, filenames []string, goVersion string, manual bool) {
+func testPkg(t *testing.T, filenames []string, manual bool) {
 	srcs := make([][]byte, len(filenames))
 	for i, filename := range filenames {
 		src, err := os.ReadFile(filename)
@@ -385,5 +415,5 @@ func testPkg(t *testing.T, filenames []string, goVersion string, manual bool) {
 		}
 		srcs[i] = src
 	}
-	checkFiles(t, nil, goVersion, filenames, srcs, manual)
+	testFiles(t, nil, filenames, srcs, manual)
 }

src/go/types/testdata/check/tmp.go2

@@ -1,17 +0,0 @@
-// Copyright 2020 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// This file is meant as "dumping ground" for debugging code.
-
-package p
-
-// fun test case
-type C[P interface{m()}] P
-
-func (r C[P]) m() { r.m() }
-
-func f[T interface{m(); n()}](x T) {
-	y := C[T](x)
-	y.m()
-}

src/go/types/testdata/manual.go2

@@ -0,0 +1,9 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file is tested when running "go test -run Manual"
+// without source arguments. Use for one-off debugging.
+
+package p
+